1. Field of the Invention
This invention relates to core memory drive systems and more particularly to a system in which a single drive current passes through both the X and Y dimensions and returns through unselected conductors in each dimension.
2. Discussion of the Prior Art
Core memory drive systems usually use a matrix of decoding diodes to couple drive currents to a selected X or Y drive conductor. Separate currents pass through each dimension so that the total drive current is equal to the sum of the X and Y partial select drive currents.
However, other drive schemes have sometimes been used. In an article by Jan A. Rajchman, "Ferrite Apertured Plate For Random Access Memory," Proceedings of the IRE, pp. 325-334 (March 1957), there is disclosed at page 331 a three dimensional noncoincident current drive arrangement using transformer switches in which a row of drive conductors is energized by energizing n-1 unselected conductors with reverse currents which accumulate at a common end for a forward drive current through the selected drive conductor. The purpose of the scheme was to reduce the drive currents generated by each transformer switch and in view of the noncoincident current drive it had no effect upon current margins or sense winding noise cancellation. Only one row of cores in a memory plate received any current at all.